Class for merging PostList objects from subdatabases. More...

#include <multi_postlist.h>

Inheritance diagram for MultiPostList:

Collaboration diagram for MultiPostList:

Public Member Functions
	MultiPostList (Xapian::doccount n_shards_, PostList **postlists_)
	Constructor. More...

	~MultiPostList ()
	Destructor. More...

Xapian::docid	get_docid () const
	Return the current docid. More...

Xapian::termcount	get_wdf () const
	Return the wdf for the document at the current position. More...

double	get_weight (Xapian::termcount doclen, Xapian::termcount unique_terms, Xapian::termcount wdfdocmax) const
	Return the weight contribution for the current position. More...

bool	at_end () const
	Return true if the current position is past the last entry in this list. More...

double	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return. More...

PositionList *	open_position_list () const
	Read the position list for the term in the current document and. More...

PostList *	next (double w_min)
	Advance the current position to the next document in the postlist. More...

PostList *	skip_to (Xapian::docid, double w_min)
	Skip forward to the specified docid. More...

std::string	get_description () const
	Return a string description of this object. More...

Public Member Functions inherited from Xapian::Internal::PostList
virtual	~PostList ()
	We have virtual methods and want to be able to delete derived classes using a pointer to the base class, so we need a virtual destructor. More...

Xapian::doccount	get_termfreq () const
	Get an estimate of the number of documents this PostList will return. More...

virtual PositionList *	read_position_list ()
	Read the position list for the term in the current document and return a pointer to it (owned by the PostList). More...

virtual PostList *	check (Xapian::docid did, double w_min, bool &valid)
	Check if the specified docid occurs in this postlist. More...

PostList *	next ()
	Advance the current position to the next document in the postlist. More...

PostList *	skip_to (Xapian::docid did)
	Skip forward to the specified docid. More...

virtual Xapian::termcount	count_matching_subqs () const
	Count the number of leaf subqueries which match at the current position. More...

virtual void	gather_position_lists (OrPositionList *orposlist)
	Gather PositionList* objects for a subtree. More...

virtual void	get_docid_range (docid &first, docid &last) const
	Get the bounds on the range of docids this PostList can return. More...

Private Member Functions
void	operator= (const MultiPostList &)=delete
	Don't allow assignment. More...

	MultiPostList (const MultiPostList &)=delete
	Don't allow copying. More...

Private Attributes
Xapian::doccount	n_shards
	Number of PostList* entries in postlists. More...

PostList **	postlists
	Sub-postlists which we use as a heap. More...

Xapian::doccount	docids_size = 0
	Number of entries in docids;. More...

Xapian::docid *	docids = nullptr
	Heap of docids from the current positions of the postlists. More...

Additional Inherited Members
Protected Member Functions inherited from Xapian::Internal::PostList
	PostList ()
	Only constructable as a base class for derived classes. More...

Protected Attributes inherited from Xapian::Internal::PostList
Xapian::doccount	termfreq
	Estimate of the number of documents this PostList will return. More...

Detailed Description

Class for merging PostList objects from subdatabases.

Definition at line 31 of file multi_postlist.h.

Constructor & Destructor Documentation

◆ MultiPostList() [1/2]

MultiPostList::MultiPostList ( const MultiPostList & )

privatedelete

Don't allow copying.

◆ MultiPostList() [2/2]

MultiPostList::MultiPostList	(	Xapian::doccount	n_shards_,
		PostList **	postlists_
	)

inline

Constructor.

Definition at line 52 of file multi_postlist.h.

References docids, Xapian::Internal::PostList::get_termfreq(), n_shards, postlists, and Xapian::Internal::PostList::termfreq.

◆ ~MultiPostList()

MultiPostList::~MultiPostList ( )

Destructor.

Definition at line 35 of file multi_postlist.cc.

Member Function Documentation

◆ at_end()

bool MultiPostList::at_end ( ) const

virtual

Return true if the current position is past the last entry in this list.

Implements Xapian::Internal::PostList.

Definition at line 67 of file multi_postlist.cc.

◆ get_description()

std::string MultiPostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::Internal::PostList.

Definition at line 183 of file multi_postlist.cc.

◆ get_docid()

Xapian::docid MultiPostList::get_docid ( ) const

virtual

Return the current docid.

Implements Xapian::Internal::PostList.

Definition at line 44 of file multi_postlist.cc.

◆ get_wdf()

Xapian::termcount MultiPostList::get_wdf ( ) const

virtual

Return the wdf for the document at the current position.

Reimplemented from Xapian::Internal::PostList.

Definition at line 50 of file multi_postlist.cc.

References shard_number().

◆ get_weight()

double MultiPostList::get_weight	(	Xapian::termcount	doclen,
		Xapian::termcount	unique_terms,
		Xapian::termcount	wdfdocmax
	)		const

virtual

Return the weight contribution for the current position.

Implements Xapian::Internal::PostList.

Definition at line 56 of file multi_postlist.cc.

References Assert.

◆ next()

PostList * MultiPostList::next ( double w_min )

virtual

Advance the current position to the next document in the postlist.

The list starts before the first entry in the list, so next(), skip_to() or check() must be called before any methods which need the context of the current position.

Parameters

w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns: If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::Internal::PostList.

Definition at line 88 of file multi_postlist.cc.

References Xapian::Internal::PostList::at_end(), Xapian::Internal::PostList::get_docid(), Heap::make(), Xapian::Internal::PostList::next(), Heap::pop(), Heap::replace(), shard_number(), and unshard().

◆ open_position_list()

PositionList * MultiPostList::open_position_list ( ) const

virtual

Read the position list for the term in the current document and.

Reimplemented from Xapian::Internal::PostList.

Definition at line 82 of file multi_postlist.cc.

References shard_number().

◆ operator=()

void MultiPostList::operator= ( const MultiPostList & )

privatedelete

Don't allow assignment.

◆ recalc_maxweight()

double MultiPostList::recalc_maxweight ( )

virtual

Recalculate the upper bound on what get_weight() can return.

Implements Xapian::Internal::PostList.

Definition at line 73 of file multi_postlist.cc.

References Assert.

◆ skip_to()

PostList * MultiPostList::skip_to	(	Xapian::docid	did,
		double	w_min
	)

virtual

Skip forward to the specified docid.

If the specified docid isn't in the list, position ourselves on the first document after it (or at_end() if no greater docids are present).

Parameters

w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns: If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::Internal::PostList.

Definition at line 130 of file multi_postlist.cc.

References Xapian::Internal::PostList::at_end(), Xapian::Internal::PostList::get_docid(), Heap::make(), Xapian::Internal::PostList::next(), shard_docid(), shard_number(), Xapian::Internal::PostList::skip_to(), and unshard().

Member Data Documentation

◆ docids

Xapian::docid* MultiPostList::docids = nullptr

private

Heap of docids from the current positions of the postlists.

Definition at line 48 of file multi_postlist.h.

Referenced by MultiPostList().

◆ docids_size

Xapian::doccount MultiPostList::docids_size = 0

private

Number of entries in docids;.

Definition at line 45 of file multi_postlist.h.

◆ n_shards

Xapian::doccount MultiPostList::n_shards

private

Number of PostList* entries in postlists.

Definition at line 39 of file multi_postlist.h.

Referenced by MultiPostList().

◆ postlists

PostList** MultiPostList::postlists

private

Sub-postlists which we use as a heap.

Definition at line 42 of file multi_postlist.h.

Referenced by MultiPostList().

The documentation for this class was generated from the following files:

backends/multi/multi_postlist.h
backends/multi/multi_postlist.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MultiPostList() [1/2]

◆ MultiPostList() [2/2]

◆ ~MultiPostList()

Member Function Documentation

◆ at_end()

◆ get_description()

◆ get_docid()

◆ get_wdf()

◆ get_weight()

◆ next()

◆ open_position_list()

◆ operator=()

◆ recalc_maxweight()

◆ skip_to()

Member Data Documentation

◆ docids

◆ docids_size

◆ n_shards

◆ postlists